An advertising agency at the centre of a row over the banning from cinema screens of an advert featuring the Lord’s Prayer will not reverse the decision.

Amid criticism from political and religious leaders, Digital Cinema Media (DCM) said it believes its policy is “correct and fair” and that “a clear neutral stance remains the fairest policy for all”.

David Cameron has denounced the ban as “ridiculous”, the Archbishop of Canterbury, the Most Rev Justin Welby, said the decision was “extraordinary” and London mayor Boris Johnson said he expected it to be reversed.

The Equality and Human Rights Commission also said it was concerned by any blanket ban on religious ads, saying “there is no right not to be offended in the UK”.

DCM, which handles adverts for Odeon, Cineworld and Vue cinemas, released a new statement amid threats from the Church of England (CoE) of legal action over the ban.

The advert, produced by JustPray.uk, shows the Lord’s Prayer being recited by members of the public ranging from bodybuilders to children, and also features the Most Rev Justin Welby.

The minute-long advert received clearance from the British Board of Film Classification and the Cinema Advertising Authority, but DCM has refused to show it.

DCM said in a statement: “While there has been passionate debate about this issue, we know that many customers support our policy.

“We believe a clear neutral stance remains the fairest policy for all, and allows DCM to treat all political and religious beliefs equally.”

The CoE initially believed the ad had been approved and would be played before showings of Star Wars: The Force Awakens from December 18.

But they were later told that due to a DCM policy not to run adverts which could potentially cause offence, the film would not be shown.

When asked for a copy of that policy, the CoE was told there was no formal policy document but that it had been agreed with DCM’s members.

A formal policy now appears on DCM’s website, stating: “To be approved, an advertisement must... not in the reasonable opinion of DCM constitute political or religious advertising.”

Today DCM tried to clarify its position on the timing of the policy’s drafting, saying it had been in place since 2008 but only recently published on its website.

DCM said: “Digital Cinema Media has a long-standing policy of not accepting ‘political or religious advertising’ content for use in its cinemas, which has been in place since our inception in 2008.

“However, we recently took the decision to make it visible on our website along with all our other terms and conditions.

“This policy has been in place for many years and we are confident it is correct and fair.”

Stephen Slack, the Church’s chief legal adviser, has warned the ban could trigger legal action under the Equality Act, which bans commercial organisations from refusing services on religious grounds.

But Terry Sanderson, the president of the National Secular Society, accused the Church of being “arrogant” to imagine that it can “foist” its opinions on captive cinema audiences.